GSL/tests/span_tests.cpp
2016-05-29 14:05:09 -07:00

1053 lines
27 KiB
C++

///////////////////////////////////////////////////////////////////////////////
//
// Copyright (c) 2015 Microsoft Corporation. All rights reserved.
//
// This code is licensed under the MIT License (MIT).
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//
///////////////////////////////////////////////////////////////////////////////
#include <UnitTest++/UnitTest++.h>
#include <span.h>
#include <iostream>
#include <list>
#include <map>
#include <memory>
#include <string>
#include <vector>
using namespace std;
using namespace gsl;
namespace
{
struct BaseClass
{
};
struct DerivedClass : BaseClass
{
};
}
SUITE(span_tests)
{
TEST(default_constructor)
{
{
span<int> s;
CHECK(s.length() == 0 && s.data() == nullptr);
span<const int> cs;
CHECK(cs.length() == 0 && cs.data() == nullptr);
}
{
span<int, 0> s;
CHECK(s.length() == 0 && s.data() == nullptr);
span<const int, 0> cs;
CHECK(cs.length() == 0 && cs.data() == nullptr);
}
{
#ifdef CONFIRM_COMPILATION_ERRORS
span<int, 1> s;
CHECK(s.length() == 1 && s.data() == nullptr); // explains why it can't compile
#endif
}
{
span<int> s{};
CHECK(s.length() == 0 && s.data() == nullptr);
span<const int> cs{};
CHECK(cs.length() == 0 && cs.data() == nullptr);
}
}
TEST(size_optimization)
{
{
span<int> s;
CHECK(sizeof(s) == sizeof(int*) + sizeof(ptrdiff_t));
}
{
span<int, 0> s;
CHECK(sizeof(s) == sizeof(int*));
}
}
TEST(from_nullptr_constructor)
{
{
span<int> s = nullptr;
CHECK(s.length() == 0 && s.data() == nullptr);
span<const int> cs = nullptr;
CHECK(cs.length() == 0 && cs.data() == nullptr);
}
{
span<int, 0> s = nullptr;
CHECK(s.length() == 0 && s.data() == nullptr);
span<const int, 0> cs = nullptr;
CHECK(cs.length() == 0 && cs.data() == nullptr);
}
{
#ifdef CONFIRM_COMPILATION_ERRORS
span<int, 1> s = nullptr;
CHECK(s.length() == 1 && s.data() == nullptr); // explains why it can't compile
#endif
}
{
span<int> s{nullptr};
CHECK(s.length() == 0 && s.data() == nullptr);
span<const int> cs{nullptr};
CHECK(cs.length() == 0 && cs.data() == nullptr);
}
{
span<int*> s{nullptr};
CHECK(s.length() == 0 && s.data() == nullptr);
span<const int*> cs{nullptr};
CHECK(cs.length() == 0 && cs.data() == nullptr);
}
}
TEST(from_nullptr_length_constructor)
{
{
span<int> s{nullptr, 0};
CHECK(s.length() == 0 && s.data() == nullptr);
span<const int> cs{nullptr, 0};
CHECK(cs.length() == 0 && cs.data() == nullptr);
}
{
span<int, 0> s{nullptr, 0};
CHECK(s.length() == 0 && s.data() == nullptr);
span<const int, 0> cs{nullptr, 0};
CHECK(cs.length() == 0 && cs.data() == nullptr);
}
{
auto workaround_macro = []() { span<int, 1> s{ nullptr, 0 }; };
CHECK_THROW(workaround_macro(), fail_fast);
}
{
auto workaround_macro = []() { span<int> s{nullptr, 1}; };
CHECK_THROW(workaround_macro(), fail_fast);
auto const_workaround_macro = []() { span<const int> cs{nullptr, 1}; };
CHECK_THROW(const_workaround_macro(), fail_fast);
}
{
auto workaround_macro = []() { span<int, 0> s{nullptr, 1}; };
CHECK_THROW(workaround_macro(), fail_fast);
auto const_workaround_macro = []() { span<const int, 0> s{nullptr, 1}; };
CHECK_THROW(const_workaround_macro(), fail_fast);
}
{
span<int*> s{nullptr, 0};
CHECK(s.length() == 0 && s.data() == nullptr);
span<const int*> cs{nullptr, 0};
CHECK(cs.length() == 0 && cs.data() == nullptr);
}
}
TEST(from_pointer_length_constructor)
{
int arr[4] = {1, 2, 3, 4};
{
span<int> s{&arr[0], 2};
CHECK(s.length() == 2 && s.data() == &arr[0]);
CHECK(s[0] == 1 && s[1] == 2);
}
{
span<int, 2> s{&arr[0], 2};
CHECK(s.length() == 2 && s.data() == &arr[0]);
CHECK(s[0] == 1 && s[1] == 2);
}
{
int* p = nullptr;
span<int> s{p, 0};
CHECK(s.length() == 0 && s.data() == nullptr);
}
{
int* p = nullptr;
auto workaround_macro = [=]() { span<int> s{p, 2}; };
CHECK_THROW(workaround_macro(), fail_fast);
}
}
TEST(from_pointer_pointer_constructor)
{
int arr[4] = {1, 2, 3, 4};
{
span<int> s{&arr[0], &arr[2]};
CHECK(s.length() == 2 && s.data() == &arr[0]);
CHECK(s[0] == 1 && s[1] == 2);
}
{
span<int, 2> s{&arr[0], &arr[2]};
CHECK(s.length() == 2 && s.data() == &arr[0]);
CHECK(s[0] == 1 && s[1] == 2);
}
{
span<int> s{&arr[0], &arr[0]};
CHECK(s.length() == 0 && s.data() == &arr[0]);
}
{
span<int, 0> s{&arr[0], &arr[0]};
CHECK(s.length() == 0 && s.data() == &arr[0]);
}
// this will fail the std::distance() precondition, which asserts on MSVC debug builds
//{
// auto workaround_macro = [&]() { span<int> s{&arr[1], &arr[0]}; };
// CHECK_THROW(workaround_macro(), fail_fast);
//}
// this will fail the std::distance() precondition, which asserts on MSVC debug builds
//{
// int* p = nullptr;
// auto workaround_macro = [&]() { span<int> s{&arr[0], p}; };
// CHECK_THROW(workaround_macro(), fail_fast);
//}
{
int* p = nullptr;
span<int> s{ p, p };
CHECK(s.length() == 0 && s.data() == nullptr);
}
{
int* p = nullptr;
span<int, 0> s{ p, p };
CHECK(s.length() == 0 && s.data() == nullptr);
}
// this will fail the std::distance() precondition, which asserts on MSVC debug builds
//{
// int* p = nullptr;
// auto workaround_macro = [&]() { span<int> s{&arr[0], p}; };
// CHECK_THROW(workaround_macro(), fail_fast);
//}
}
TEST(from_array_constructor)
{
int arr[5] = {1, 2, 3, 4, 5};
{
span<int> s{arr};
CHECK(s.length() == 5 && s.data() == &arr[0]);
}
{
span<int, 5> s{arr};
CHECK(s.length() == 5 && s.data() == &arr[0]);
}
int arr2d[2][3] = { 1, 2, 3, 4, 5, 6 };
#ifdef CONFIRM_COMPILATION_ERRORS
{
span<int, 6> s{arr};
}
{
span<int, 0> s{arr};
CHECK(s.length() == 0 && s.data() == &arr[0]);
}
{
span<int> s{arr2d};
CHECK(s.length() == 6 && s.data() == &arr2d[0][0]);
CHECK(s[0] == 1 && s[5] == 6);
}
{
span<int, 0> s{arr2d};
CHECK(s.length() == 0 && s.data() == &arr2d[0][0]);
}
{
span<int, 6> s{ arr2d };
}
#endif
{
span<int[3]> s{ &(arr2d[0]), 1 };
CHECK(s.length() == 1 && s.data() == &arr2d[0]);
}
int arr3d[2][3][2] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12};
#ifdef CONFIRM_COMPILATION_ERRORS
{
span<int> s{arr3d};
CHECK(s.length() == 12 && s.data() == &arr3d[0][0][0]);
CHECK(s[0] == 1 && s[11] == 12);
}
{
span<int, 0> s{arr3d};
CHECK(s.length() == 0 && s.data() == &arr3d[0][0][0]);
}
{
span<int, 11> s{arr3d};
}
{
span<int, 12> s{arr3d};
CHECK(s.length() == 12 && s.data() == &arr3d[0][0][0]);
CHECK(s[0] == 1 && s[5] == 6);
}
#endif
{
span<int[3][2]> s{&arr3d[0], 1};
CHECK(s.length() == 1 && s.data() == &arr3d[0]);
}
}
TEST(from_dynamic_array_constructor)
{
double(*arr)[3][4] = new double[100][3][4];
{
span<double> s(&arr[0][0][0], 10);
CHECK(s.length() == 10 && s.data() == &arr[0][0][0]);
}
delete[] arr;
}
TEST(from_std_array_constructor)
{
std::array<int, 4> arr = {1, 2, 3, 4};
{
span<int> s{arr};
CHECK(s.size() == narrow_cast<ptrdiff_t>(arr.size()) && s.data() == arr.data());
span<const int> cs{arr};
CHECK(cs.size() == narrow_cast<ptrdiff_t>(arr.size()) && cs.data() == arr.data());
}
{
span<int, 4> s{arr};
CHECK(s.size() == narrow_cast<ptrdiff_t>(arr.size()) && s.data() == arr.data());
span<const int, 4> cs{arr};
CHECK(cs.size() == narrow_cast<ptrdiff_t>(arr.size()) && cs.data() == arr.data());
}
#ifdef CONFIRM_COMPILATION_ERRORS
{
span<int, 2> s{arr};
CHECK(s.size() == 2 && s.data() == arr.data());
span<const int, 2> cs{arr};
CHECK(cs.size() == 2 && cs.data() == arr.data());
}
{
span<int, 0> s{arr};
CHECK(s.size() == 0 && s.data() == arr.data());
span<const int, 0> cs{arr};
CHECK(cs.size() == 0 && cs.data() == arr.data());
}
{
span<int, 5> s{arr};
}
{
auto get_an_array = []()->std::array<int, 4> { return{1, 2, 3, 4}; };
auto take_a_span = [](span<int> s) { (void)s; };
// try to take a temporary std::array
take_a_span(get_an_array());
}
#endif
{
auto get_an_array = []() -> std::array<int, 4> { return { 1, 2, 3, 4 }; };
auto take_a_span = [](span<const int> s) { (void)s; };
// try to take a temporary std::array
take_a_span(get_an_array());
}
}
TEST(from_const_std_array_constructor)
{
const std::array<int, 4> arr = {1, 2, 3, 4};
{
span<const int> s{arr};
CHECK(s.size() == narrow_cast<ptrdiff_t>(arr.size()) && s.data() == arr.data());
}
{
span<const int, 4> s{arr};
CHECK(s.size() == narrow_cast<ptrdiff_t>(arr.size()) && s.data() == arr.data());
}
#ifdef CONFIRM_COMPILATION_ERRORS
{
span<const int, 2> s{arr};
CHECK(s.size() == 2 && s.data() == arr.data());
}
{
span<const int, 0> s{arr};
CHECK(s.size() == 0 && s.data() == arr.data());
}
{
span<const int, 5> s{arr};
}
{
auto get_an_array = []() -> const std::array<int, 4> { return {1, 2, 3, 4}; };
auto take_a_span = [](span<const int> s) { (void) s; };
// try to take a temporary std::array
take_a_span(get_an_array());
}
#endif
}
TEST(from_container_constructor)
{
std::vector<int> v = {1, 2, 3};
const std::vector<int> cv = v;
{
span<int> s{v};
CHECK(s.size() == narrow_cast<std::ptrdiff_t>(v.size()) && s.data() == v.data());
span<const int> cs{v};
CHECK(cs.size() == narrow_cast<std::ptrdiff_t>(v.size()) && cs.data() == v.data());
}
std::string str = "hello";
const std::string cstr = "hello";
{
#ifdef CONFIRM_COMPILATION_ERRORS
span<char> s{str};
CHECK(s.size() == narrow_cast<std::ptrdiff_t>(str.size()) && s.data() == str.data());
#endif
span<const char> cs{str};
CHECK(cs.size() == narrow_cast<std::ptrdiff_t>(str.size()) && cs.data() == str.data());
}
{
#ifdef CONFIRM_COMPILATION_ERRORS
span<char> s{cstr};
#endif
span<const char> cs{cstr};
CHECK(cs.size() == narrow_cast<std::ptrdiff_t>(cstr.size()) &&
cs.data() == cstr.data());
}
{
#ifdef CONFIRM_COMPILATION_ERRORS
auto get_temp_vector = []() -> std::vector<int> { return {}; };
auto use_span = [](span<int> s) { (void) s; };
use_span(get_temp_vector());
#endif
}
{
auto get_temp_vector = []() -> std::vector<int> { return{}; };
auto use_span = [](span<const int> s) { (void)s; };
use_span(get_temp_vector());
}
{
#ifdef CONFIRM_COMPILATION_ERRORS
auto get_temp_string = []() -> std::string { return{}; };
auto use_span = [](span<char> s) { (void)s; };
use_span(get_temp_string());
#endif
}
{
auto get_temp_string = []() -> std::string { return {}; };
auto use_span = [](span<const char> s) { (void) s; };
use_span(get_temp_string());
}
{
#ifdef CONFIRM_COMPILATION_ERRORS
auto get_temp_vector = []() -> const std::vector<int> { return {}; };
auto use_span = [](span<const char> s) { (void) s; };
use_span(get_temp_vector());
#endif
}
{
#ifdef CONFIRM_COMPILATION_ERRORS
auto get_temp_string = []() -> const std::string { return {}; };
auto use_span = [](span<const char> s) { (void) s; };
use_span(get_temp_string());
#endif
}
{
#ifdef CONFIRM_COMPILATION_ERRORS
std::map<int, int> m;
span<int> s{m};
#endif
}
}
TEST(from_convertible_span_constructor)
{
{
span<DerivedClass> avd;
span<const DerivedClass> avcd = avd;
(void)avcd;
}
{
#ifdef CONFIRM_COMPILATION_ERRORS
span<DerivedClass> avd;
span<BaseClass> avb = avd;
(void) avb;
#endif
}
{
span<int> s;
span<unsigned int> s2 = s;
(void)s2;
}
{
span<int> s;
span<const unsigned int> s2 = s;
(void)s2;
}
{
#ifdef CONFIRM_COMPILATION_ERRORS
span<int> s;
span<short> s2 = s;
(void)s2;
#endif
}
}
TEST(copy_move_and_assignment)
{
span<int> s1;
CHECK(s1.empty());
int arr[] = {3, 4, 5};
span<const int> s2 = arr;
CHECK(s2.length() == 3 && s2.data() == &arr[0]);
s2 = s1;
CHECK(s2.empty());
auto get_temp_span = [&]() -> span<int> { return {&arr[1], 2}; };
auto use_span = [&](span<const int> s) { CHECK(s.length() == 2 && s.data() == &arr[1]); };
use_span(get_temp_span());
s1 = get_temp_span();
CHECK(s1.length() == 2 && s1.data() == &arr[1]);
}
TEST(first)
{
int arr[5] = {1, 2, 3, 4, 5};
{
span<int, 5> av = arr;
CHECK(av.first<2>().length() == 2);
CHECK(av.first(2).length() == 2);
}
{
span<int, 5> av = arr;
CHECK(av.first<0>().length() == 0);
CHECK(av.first(0).length() == 0);
}
{
span<int, 5> av = arr;
CHECK(av.first<5>().length() == 5);
CHECK(av.first(5).length() == 5);
}
{
span<int, 5> av = arr;
#ifdef CONFIRM_COMPILATION_ERRORS
CHECK(av.first<6>().length() == 6);
CHECK(av.first<-1>().length() == -1);
#endif
CHECK_THROW(av.first(6).length(), fail_fast);
}
{
span<int> av;
CHECK(av.first<0>().length() == 0);
CHECK(av.first(0).length() == 0);
}
}
TEST(last)
{
int arr[5] = {1, 2, 3, 4, 5};
{
span<int, 5> av = arr;
CHECK(av.last<2>().length() == 2);
CHECK(av.last(2).length() == 2);
}
{
span<int, 5> av = arr;
CHECK(av.last<0>().length() == 0);
CHECK(av.last(0).length() == 0);
}
{
span<int, 5> av = arr;
CHECK(av.last<5>().length() == 5);
CHECK(av.last(5).length() == 5);
}
{
span<int, 5> av = arr;
#ifdef CONFIRM_COMPILATION_ERRORS
CHECK(av.last<6>().length() == 6);
#endif
CHECK_THROW(av.last(6).length(), fail_fast);
}
{
span<int> av;
CHECK(av.last<0>().length() == 0);
CHECK(av.last(0).length() == 0);
}
}
TEST(subspan)
{
int arr[5] = {1, 2, 3, 4, 5};
{
span<int, 5> av = arr;
CHECK((av.subspan<2, 2>().length() == 2));
CHECK(av.subspan(2, 2).length() == 2);
CHECK(av.subspan(2, 3).length() == 3);
}
{
span<int, 5> av = arr;
CHECK((av.subspan<0, 0>().length() == 0));
CHECK(av.subspan(0, 0).length() == 0);
}
{
span<int, 5> av = arr;
CHECK((av.subspan<0, 5>().length() == 5));
CHECK(av.subspan(0, 5).length() == 5);
CHECK_THROW(av.subspan(0, 6).length(), fail_fast);
CHECK_THROW(av.subspan(1, 5).length(), fail_fast);
}
{
span<int, 5> av = arr;
CHECK((av.subspan<4, 0>().length() == 0));
CHECK(av.subspan(4, 0).length() == 0);
CHECK(av.subspan(5, 0).length() == 0);
CHECK_THROW(av.subspan(6, 0).length(), fail_fast);
}
{
span<int> av;
CHECK((av.subspan<0, 0>().length() == 0));
CHECK(av.subspan(0, 0).length() == 0);
CHECK_THROW((av.subspan<1, 0>().length()), fail_fast);
}
{
span<int> av;
CHECK(av.subspan(0).length() == 0);
CHECK_THROW(av.subspan(1).length(), fail_fast);
}
{
span<int> av = arr;
CHECK(av.subspan(0).length() == 5);
CHECK(av.subspan(1).length() == 4);
CHECK(av.subspan(4).length() == 1);
CHECK(av.subspan(5).length() == 0);
CHECK_THROW(av.subspan(6).length(), fail_fast);
auto av2 = av.subspan(1);
for (int i = 0; i < 4; ++i) CHECK(av2[i] == i + 2);
}
{
span<int, 5> av = arr;
CHECK(av.subspan(0).length() == 5);
CHECK(av.subspan(1).length() == 4);
CHECK(av.subspan(4).length() == 1);
CHECK(av.subspan(5).length() == 0);
CHECK_THROW(av.subspan(6).length(), fail_fast);
auto av2 = av.subspan(1);
for (int i = 0; i < 4; ++i) CHECK(av2[i] == i + 2);
}
}
TEST(operator_function_call)
{
int arr[4] = {1, 2, 3, 4};
{
span<int> s = arr;
CHECK(s(0) == 1);
CHECK_THROW(s(5), fail_fast);
}
{
int arr2d[2] = {1, 6};
span<int, 2> s = arr2d;
CHECK(s(0) == 1);
CHECK(s(1) == 6);
CHECK_THROW(s(2) ,fail_fast);
}
}
TEST(iterator)
{
span<int>::iterator it1;
span<int>::iterator it2;
CHECK(it1 == it2);
}
TEST(begin_end)
{
{
int a[] = { 1, 2, 3, 4 };
span<int> s = a;
span<int>::iterator it = s.begin();
auto first = it;
CHECK(it == first);
CHECK(*it == 1);
span<int>::iterator beyond = s.end();
CHECK(it != beyond);
CHECK_THROW(*beyond, fail_fast);
CHECK(beyond - first == 4);
CHECK(first - first == 0);
CHECK(beyond - beyond == 0);
++it;
CHECK(it - first == 1);
CHECK(*it == 2);
*it = 22;
CHECK(*it == 22);
CHECK(beyond - it == 3);
it = first;
CHECK(it == first);
while (it != s.end())
{
*it = 5;
++it;
}
CHECK(it == beyond);
CHECK(it - beyond == 0);
for (auto& n : s)
CHECK(n == 5);
}
}
TEST(comparison_operators)
{
{
span<int> s1 = nullptr;
span<int> s2 = nullptr;
CHECK(s1 == s2);
CHECK(!(s1 != s2));
CHECK(!(s1 < s2));
CHECK(s1 <= s2);
CHECK(!(s1 > s2));
CHECK(s1 >= s2);
CHECK(s2 == s1);
CHECK(!(s2 != s1));
CHECK(!(s2 < s1));
CHECK(s2 <= s1);
CHECK(!(s2 > s1));
CHECK(s2 >= s1);
}
{
int arr[] = {2, 1};
span<int> s1 = arr;
span<int> s2 = arr;
CHECK(s1 == s2);
CHECK(!(s1 != s2));
CHECK(!(s1 < s2));
CHECK(s1 <= s2);
CHECK(!(s1 > s2));
CHECK(s1 >= s2);
CHECK(s2 == s1);
CHECK(!(s2 != s1));
CHECK(!(s2 < s1));
CHECK(s2 <= s1);
CHECK(!(s2 > s1));
CHECK(s2 >= s1);
}
{
int arr[] = {2, 1}; // bigger
span<int> s1 = nullptr;
span<int> s2 = arr;
CHECK(s1 != s2);
CHECK(s2 != s1);
CHECK(!(s1 == s2));
CHECK(!(s2 == s1));
CHECK(s1 < s2);
CHECK(!(s2 < s1));
CHECK(s1 <= s2);
CHECK(!(s2 <= s1));
CHECK(s2 > s1);
CHECK(!(s1 > s2));
CHECK(s2 >= s1);
CHECK(!(s1 >= s2));
}
{
int arr1[] = {1, 2};
int arr2[] = {1, 2};
span<int> s1 = arr1;
span<int> s2 = arr2;
CHECK(s1 == s2);
CHECK(!(s1 != s2));
CHECK(!(s1 < s2));
CHECK(s1 <= s2);
CHECK(!(s1 > s2));
CHECK(s1 >= s2);
CHECK(s2 == s1);
CHECK(!(s2 != s1));
CHECK(!(s2 < s1));
CHECK(s2 <= s1);
CHECK(!(s2 > s1));
CHECK(s2 >= s1);
}
{
int arr[] = {1, 2, 3};
span<int> s1 = {&arr[0], 2}; // shorter
span<int> s2 = arr; // longer
CHECK(s1 != s2);
CHECK(s2 != s1);
CHECK(!(s1 == s2));
CHECK(!(s2 == s1));
CHECK(s1 < s2);
CHECK(!(s2 < s1));
CHECK(s1 <= s2);
CHECK(!(s2 <= s1));
CHECK(s2 > s1);
CHECK(!(s1 > s2));
CHECK(s2 >= s1);
CHECK(!(s1 >= s2));
}
{
int arr1[] = {1, 2}; // smaller
int arr2[] = {2, 1}; // bigger
span<int> s1 = arr1;
span<int> s2 = arr2;
CHECK(s1 != s2);
CHECK(s2 != s1);
CHECK(!(s1 == s2));
CHECK(!(s2 == s1));
CHECK(s1 < s2);
CHECK(!(s2 < s1));
CHECK(s1 <= s2);
CHECK(!(s2 <= s1));
CHECK(s2 > s1);
CHECK(!(s1 > s2));
CHECK(s2 >= s1);
CHECK(!(s1 >= s2));
}
}
#if 0
TEST(fixed_size_conversions)
{
int arr[] = {1, 2, 3, 4};
// converting to an span from an equal size array is ok
span<int, 4> av4 = arr;
CHECK(av4.length() == 4);
// converting to dynamic_range a_v is always ok
{
span<int, dynamic_range> av = av4;
(void) av;
}
{
span<int, dynamic_range> av = arr;
(void) av;
}
// initialization or assignment to static span that REDUCES size is NOT ok
#ifdef CONFIRM_COMPILATION_ERRORS
{
span<int, 2> av2 = arr;
}
{
span<int, 2> av2 = av4;
}
#endif
{
span<int, dynamic_range> av = arr;
span<int, 2> av2 = av;
(void) av2;
}
#ifdef CONFIRM_COMPILATION_ERRORS
{
span<int, dynamic_range> av = arr;
span<int, 2, 1> av2 = av.as_span(dim<2>(), dim<2>());
}
#endif
{
span<int, dynamic_range> av = arr;
span<int, 2, 1> av2 = as_span(av, dim<>(2), dim<>(2));
auto workaround_macro = [&]() { return av2[{1, 0}] == 2; };
CHECK(workaround_macro());
}
// but doing so explicitly is ok
// you can convert statically
{
span<int, 2> av2 = {arr, 2};
(void) av2;
}
{
span<int, 1> av2 = av4.first<1>();
(void) av2;
}
// ...or dynamically
{
// NB: implicit conversion to span<int,2> from span<int,dynamic_range>
span<int, 1> av2 = av4.first(1);
(void) av2;
}
// initialization or assignment to static span that requires size INCREASE is not ok.
int arr2[2] = {1, 2};
#ifdef CONFIRM_COMPILATION_ERRORS
{
span<int, 4> av4 = arr2;
}
{
span<int, 2> av2 = arr2;
span<int, 4> av4 = av2;
}
#endif
{
auto f = [&]() {
span<int, 4> av9 = {arr2, 2};
(void) av9;
};
CHECK_THROW(f(), fail_fast);
}
// this should fail - we are trying to assign a small dynamic a_v to a fixed_size larger one
span<int, dynamic_range> av = arr2;
auto f = [&]() {
span<int, 4> av2 = av;
(void) av2;
};
CHECK_THROW(f(), fail_fast);
}
TEST(as_writeable_bytes)
{
int a[] = {1, 2, 3, 4};
{
#ifdef CONFIRM_COMPILATION_ERRORS
// you should not be able to get writeable bytes for const objects
span<const int, dynamic_range> av = a;
auto wav = av.as_writeable_bytes();
#endif
}
{
span<int, dynamic_range> av;
auto wav = as_writeable_bytes(av);
CHECK(wav.length() == av.length());
CHECK(wav.length() == 0);
CHECK(wav.size_bytes() == 0);
}
{
span<int, dynamic_range> av = a;
auto wav = as_writeable_bytes(av);
CHECK(wav.data() == (byte*) &a[0]);
CHECK(wav.length() == sizeof(a));
}
}
#endif
}
int main(int, const char* []) { return UnitTest::RunAllTests(); }